get_spans

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

No annotations are provided, so the description carries the burden. It states it returns a JSON array of span objects and includes a default limit of 50, but does not explicitly disclose that it is read-only or non-destructive. The verb 'Fetch' implies a read operation, but behavioral traits like side effects are not addressed.

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?

The description is concise, front-loading the purpose in one sentence, then listing parameters in a structured format. Every element earns its place with no wasted words.

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?

Given the tool's simplicity (3 optional parameters, no nested objects, output schema exists), the description adequately covers all necessary information: purpose, parameter explanations, and return type. The output schema is present, so return value details are not required.

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?

The description provides clear, explanatory text for each parameter (e.g., 'Filter to this session. Optional.'), which adds significant meaning beyond the minimal schema properties. With 0% schema coverage, the description fully compensates.

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 'Fetch recent agent spans' with a specific verb and resource. It distinguishes from sibling tools like get_agent_runs and get_glossary by specifying the resource (spans) and optional filters.

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 mentions optional filters (session_id, run_id) which imply usage context, but does not provide explicit when-to-use or when-not-to-use guidance, nor does it reference alternatives among many sibling tools.

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