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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real context beyond that — the scope of stripping (120+ ad-tracking and click-ID parameters) and canonicalization semantics shown by the mixed-case example URL — but it does not say whether stripping is configurable, which parameters count as tracking, or what the response contains.

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?

One front-loaded sentence carrying purpose, scope and outcome, followed by the endpoint path in parentheses. No filler, no restatement of the title, nothing that could be cut.

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?

This is a low-complexity, one-required-parameter, read-only tool with full schema coverage and explicit annotations, so the description covers what an agent needs in order to call it correctly. The one gap is the absence of an output schema combined with no statement of the return shape (the normalized URL string, and whether removed parameters are reported back).

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% and the schema example itself shows the accepted URL form including a tracking parameter, so the schema does the heavy lifting. The description adds no further meaning about the single `url` parameter (no notes on accepted schemes, whether ports are dropped, or how malformed input is handled), so the baseline of 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?

The description gives a specific verb phrase plus resource: 'Canonicalize URLs and strip 120+ ad-tracking and click-ID parameters', and states the outcome ('clean deduplication'). It also names the endpoint (POST /v1/url-normalizer), so the agent knows exactly what capability this is and that it is distinct from all listed siblings (none of which are URL utilities).

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 phrase 'for clean deduplication' implies the use case (deduping link sets before storage or comparison), but there is no explicit when-to-use/when-not-to-use statement and no named alternative. With a single-class tool and no overlapping sibling, the omission is tolerable but the guidance remains implied rather than stated.

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