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

Beyond readOnlyHint=true, the description discloses concrete behavioral traits: a 20-item display window, a `total` that counts up to 200 active projects, a `truncated: true` signal, and the sort order (last change) with the consequence that older projects drop out first. This is exactly the kind of pagination/truncation context annotations cannot express.

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?

A compact three-sentence block that front-loads purpose, then routing advice, then the pagination caveat. Every clause carries information; nothing restates the name or annotations.

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 fully by naming the returned fields, the truncation flag, the item cap, and the ordering rule. An agent knows what it will get back and how to interpret a cut-off list.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline for a no-param tool is 4. The description correctly focuses entirely on output semantics rather than inventing parameter guidance.

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 ('List FilmLab projects') and names the fields returned (id, title, current pipeline stage). This clearly distinguishes it from the single-project sibling lab_get_project and the other lab_list_* tools.

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?

Gives explicit workflow guidance: 'Call this first to find a project_id for the other tools,' which tells the agent both when to invoke it and what it feeds into. No exclusions are stated, but the routing intent is unambiguous, so an agent can place it correctly in a sequence.

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