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

Annotations already cover read-only and open-world behavior, so the bar is lower, and the description still adds meaningful context: no file, purchase, login or creator-account request is made, and download instructions, community text, account/purchase links and credential-bearing links are excluded from output. That tells an agent the call is safe but yields a deliberately trimmed payload. It does not mention rate limiting, caching, or failure modes for rejected URLs.

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?

Purpose and return fields are front-loaded, which is good, but the back half is a long run-on validation clause that duplicates the schema's own parameter description. Roughly a third of the text is redundant against structured fields rather than adding value.

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?

An output schema exists, so the return-value enumeration is technically surplus, yet the safety and exclusion notes are genuinely useful for a scraper-style open-world fetch. Combined with the strict URL contract, an agent has enough to call it correctly; only the sibling routing remains unspecified.

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 single parameter's description already contains the rejection rules and the example URL. The description restates those same constraints (queries, fragments, credentials, ports, unrelated hosts, profile roots) nearly verbatim, adding the one extra nuance that a promotion or sale link is not interchangeable — but that nuance also appears in the schema. 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 one public itch.io creator project page', then enumerates exactly what is returned (project ID, canonical URL, title, summary, description, cover URL, More-information rows). The 'one project page' framing separates it from the itchio_browse/catalog family, but no sibling is named, so an agent must infer the boundary rather than being told it.

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 gives a real precondition — the url must be a public HTTPS creator.itch.io project URL taken from a native project card — which implies a fetch-card-then-call workflow. However, it never says when to use this versus itchio_browse or itchio_catalog, and the only exclusions given are URL-shape rules rather than use-case exclusions.

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