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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety profile is covered. The description adds real behavioral context beyond them: only *published* content is returned (drafts excluded), and the default is all languages unless `lang` narrows it. It does not cover pagination or payload size, keeping 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?

Two sentences, zero waste, and the most decision-relevant fact (what you get back) is front-loaded before the optional-language note.

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?

With no output schema, the description compensates by enumerating the returned fields, and annotations carry the safety profile. An agent has everything needed to decide to call it and what to expect.

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 `slug` and `lang` are already documented with examples and the omit-for-all-languages default. The description restates the lang behavior without adding format or edge-case detail, so the 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 ('Full published content for one project') and enumerates exactly what is returned: description, unit types, payment plan, amenities, FAQs, images, canonical URL. This is clearly distinguishable from the list/search siblings by being a single-project detail fetch.

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?

Usage is implied rather than stated: the tool is for retrieving full detail of one project given a slug. The only explicit guidance is 'Pass `lang` to get one language instead of all of them', which is a parameter behavior, not a when-to-use rule. No mention of when to prefer search_projects or how to obtain the slug (that hint lives in the schema).

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