Skip to main content
Glama
Arize-ai

@arizeai/phoenix-mcp

Official
by Arize-ai

get-spans

Retrieve spans from a project using filters such as time range, trace IDs, names, or status codes for analysis.

Instructions

Get spans from a project with filtering criteria.

Spans represent individual operations or units of work within a trace. They contain timing information, attributes, and context about the operation being performed.

Example usage: Get recent spans from project "my-project" Get spans in a time range from project "my-project"

Expected return: Object containing spans array and optional next cursor for pagination. Example: { "spans": [ { "id": "span123", "name": "http_request", "context": { "trace_id": "trace456", "span_id": "span123" }, "start_time": "2024-01-01T12:00:00Z", "end_time": "2024-01-01T12:00:01Z", "attributes": { "http.method": "GET", "http.url": "/api/users" } } ], "nextCursor": "cursor_for_pagination" }

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
project_identifierNo
start_timeNo
end_timeNo
trace_idsNo
parent_idNo
namesNo
span_kindsNo
status_codesNo
cursorNo
limitNo
include_annotationsNo
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description partially covers behavior by showing expected return format and pagination via cursor. However, it does not disclose read-only nature, auth requirements, or rate limits. Adds some value but lacks full transparency.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Description is front-loaded with purpose, includes an example, and is reasonably concise. The example adds length but is useful. Minor redundancy could be trimmed.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the high parameter count (11), no output schema, and no annotations, the description is insufficient. It does not cover all parameters, lacks guidance on when to use, and only provides a partial return example.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the description fails to explain any parameter semantics. The example only illustrates a few fields without detailing the 11 parameters or their meanings. Does not add needed meaning.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool retrieves spans with filtering, explaining what spans are. It distinguishes from sibling tools like get-trace implicitly, but lacks an explicit differentiation statement.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides example usage but does not specify when to use this tool vs alternatives, nor does it mention when not to use it. No guidance on context or exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/Arize-ai/phoenix'

If you have feedback or need assistance with the MCP directory API, please join our Discord server