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

The annotations declare readOnlyHint=true, destructiveHint=false and idempotentHint=true, so the safety profile is already documented. The description reinforces this in plain language ('opens nothing by itself') and adds the return shape (step-by-step screens, buttons, fields), which goes beyond the annotations. The remark about Timetastic's REST API and lack of an official MCP server is contextual background rather than behavioral disclosure about this call.

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?

The useful content is front-loaded and the critical clarification ('returns steps, opens nothing') appears early. However, the final sentence about Timetastic's official API, bearer token and MCP server status answers a question the agent did not ask in order to invoke this tool, and it lengthens the definition without helping selection or invocation.

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?

For a zero-parameter, no-output-schema tool, this is close to complete: it says what comes back (step-by-step instructions) and what to do next (the cotlet_browser_* tools). What is missing is any hint about what the returned steps will cover, for example whether the agent needs dates or leave type ready, or whether the user must be signed in to the Cloud Browser first.

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 no parameter meaning to add; the baseline for a parameterless tool is 4. Nothing in the description conflicts with the empty schema. No deduction is warranted here.

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?

While the first sentence says 'Book time off', the second immediately corrects the impression: the tool 'Returns how to do it in Timetastic step by step (screens, buttons, fields) and opens nothing by itself.' That is a specific statement of what the tool actually does. It also distinguishes itself from the cotlet_browser_* tools it delegates execution to. It does not differentiate from cotlet_app_guide, which likely covers similar ground.

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 description gives a clear context ('in the user's own Timetastic account') and an explicit hand-off: get the steps here, then execute them with the cotlet_browser_* tools in the Timetastic Cloud Browser. This is useful routing guidance. It stops short of stating when NOT to use this tool, for example when cotlet_app_guide or a direct API call would be preferable.

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