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

With no annotations, the description carries the full burden. It discloses the return structure ({id, title, text, url, metadata}) and explains that text is the full JSON profile, matching get_gene/get_cell_line. It also mentions the id format. It doesn't cover error handling, but for a read-only fetch this is reasonably transparent.

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 exactly two sentences, each containing crucial information: purpose, input example, output format, relationship to siblings, and the prerequisite. No filler or redundancy.

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 tool with no output schema, the description covers purpose, usage, input format, output structure, and prerequisite. It also references sibling tools for context. It lacks edge-case behavior, but that is minor and not needed for this simple tool.

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 coverage is 100%, with the schema already describing the id format and examples. The description largely repeats the examples without adding new parameter-level semantics. Thus, baseline 3 is appropriate.

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 'fetches the full record for an id returned by search', which is a specific verb+resource. It also distinguishes itself from siblings by referencing that it returns the same data as get_gene/get_cell_line, clarifying its role.

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?

It explicitly instructs to 'Always call search first to obtain a valid id', establishing a clear usage prerequisite. It does not explicitly exclude alternatives like get_gene/get_cell_line, but the reference to them implies when fetch is appropriate (when you already have a search id).

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