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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context by stating the return shape ('Returns the object under `data`') and the kind of state information provided (scheduled/live/ended). This goes beyond the annotations without contradicting them.

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

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

Three sentences with no fluff. The core purpose is front-loaded, the use case is stated, and the return location is given. Every sentence earns its place.

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

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

For a single-parameter read-only tool with a rich output schema, the description is nearly complete. It covers what the tool does, when to use it, and where the result appears. It doesn't describe pagination or rate limits, but those are less critical for a single-ID detail lookup with an output schema present.

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

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

Schema description coverage is 100%, so the schema already documents the single parameter (space_id). The description adds context about what the ID is used for ('by its space ID') but doesn't add format or source details beyond the schema. Baseline 3 is appropriate when the schema fully covers the parameter.

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

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

The description clearly states the tool retrieves details of an X Space by ID, listing the specific fields (title, state, host, participants, scheduling) and the use case (checking whether a Space is scheduled, live, or ended). It distinguishes itself from sibling tools by focusing on Space detail rather than tweets, users, or communities.

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

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

The description explicitly says when to use it: 'Use this to check whether a Space is scheduled, live, or ended, and who is hosting, before deciding to reference or attend it.' This provides clear context and a decision-oriented purpose, though it doesn't name a specific alternative tool to use instead.

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