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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: it states the exact shape of the result and, importantly, decodes the non-obvious takes_url flag as 'whether audit_url can build a run link for a specific site', which enables chaining. It does not say what happens with a vague need or an empty match set, which keeps it below 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?

It is a single front-loaded sentence that puts the input first and the return payload second, with the examples parenthetical doing useful work. It is dense rather than bloated, though the example list plus the takes_url explanation in one sentence makes it slightly hard to scan.

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?

The tool is low complexity, an output schema exists, and the description still bothers to explain the one non-obvious return field (takes_url), which is exactly the extra information an agent needs for chaining into audit_url. Missing only edge-case behavior for weak or unmatched needs.

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 all three parameters (need, limit, category) are already documented with constraints, defaults, and an enum. The description reinforces the semantics of 'need' with concrete example queries, but adds nothing about limit or category. Baseline 3 applies because the schema does the heavy lifting.

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 names a concrete input (a plain-language website need) and a concrete output (a short ranked list of free jwatte.com tools with title, one-line description, link, and takes_url). It conveys the discovery/router role clearly enough that an agent can distinguish it from audit_url, but it never explicitly contrasts itself with list_audit_tools or the other siblings.

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?

Four example phrasings ('is my site accessible', 'why is my page slow') give a good sense of the intended input style, which implies when to reach for this tool. However, there is no explicit when-not guidance and no named alternative (e.g. 'use list_audit_tools if you already know you want a full catalog'), so the routing decision is left to inference.

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