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

With no annotations, the description carries the full burden and does well: it discloses that facts are sourced and dated, that there is a 'list of what was NOT checked,' and an unusual trust guarantee ('no vendor pays for placement'). It does not cover access/permission needs or any rate or latency behavior, which keeps it short of a 5.

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?

Four short sentences, front-loaded with what is returned and followed by scope limits, neutrality, and a usage trigger. Every sentence carries information; only the neutrality clause borders on promotional framing.

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?

There is no output schema, so the description must describe returns, and it does: enumerates the fact fields, the per-situation pick, and the 'what was NOT checked' list. Combined with an unambiguous usage trigger, an agent has everything needed to select and invoke it correctly.

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 both 'category' and 'situation' are already documented in the schema, including the important note that 'situation' does not change the answer. The description adds essentially no parameter-level detail beyond restating the category scope, so baseline 3 applies.

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?

States a specific verb and resource: 'Get sourced, dated facts for every option in one category,' and enumerates the fact dimensions returned. It implicitly contrasts with the sibling 'option' tool (single option vs. every option in a category) and 'list_categories' (referenced via the schema), but never names an alternative explicitly.

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?

'Use before choosing a library or service' gives a clear, actionable trigger for invocation. It stops short of naming when NOT to use it or which sibling to reach for instead (e.g. 'option' for a single library, 'request_category' when the category is missing).

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