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

With no annotations provided, the description carries the full burden of disclosing behavior. It states what the fetch returns (section anchor, version, equations, table cells, links, attribution), implying a read-only retrieval. It does not mention error handling or what happens for invalid IDs, but for a simple fetch operation this is adequate.

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 a single, front-loaded sentence that states the purpose immediately and includes all necessary details without redundancy. Every clause adds information (fetch, ID source, content components), making it highly efficient.

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 simple fetch with one parameter and no output schema, the description provides sufficient context: it explains what to pass and what to expect in return. It does not cover error scenarios or relationship to other tools beyond search_evidence, but these are not critical for a basic get-by-ID operation.

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 schema provides an empty description for evidence_id, and schema description coverage is 0%. The description compensates by specifying that the evidence_id is 'returned from search_evidence,' giving the parameter origin and expected semantic meaning. This is essential for correct invocation but does not include format constraints or examples.

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 a specific verb ('Fetch') and a specific resource ('complete original evidence block'), and differentiates from search_evidence by specifying that it retrieves the full block using an ID. It also enumerates the returned content (section anchor, version, equations, etc.), adding concreteness beyond a generic fetch.

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 states that the evidence_id is 'returned from search_evidence,' which gives clear guidance on the correct usage flow (search first, then fetch). However, it does not explicitly mention when not to use this tool or contrast with other sibling tools like dataset_overview or list_sources, so it lacks explicit exclusions.

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