create_time_block

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

Annotations only establish that this is a non-read, non-idempotent, non-destructive operation. The description goes far beyond that: it discloses the internal mechanism (/doc/create with db='PlannerItems'), the Full Access Token requirement, the client-side id quirk caused by /doc/create not echoing the server id, and live-test evidence (accepted, listed in /todayTimeBlocks, renders correctly). This is exactly the kind of hidden behavioral context an agent needs.

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 purpose is front-loaded in the first sentence, and the experimental caveat appears immediately after. The trailing verification details are thorough but somewhat verbose, repeating the date twice and including minor specifics (app 1.70.0.0, PWA + desktop) that could be trimmed without losing the trust-calibration 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?

For a tool that is a workaround with no official endpoint, the description is unusually complete: it explains the mechanism, auth requirement, id-handling behavior, downstream usage in task creation, and verification steps. Combined with the existing output schema and full param schema, nothing an agent needs to call it correctly is missing.

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%, with all four parameters (title, date, start_time, duration_minutes) already documented with formats and examples. The description adds no per-parameter detail beyond the schema, which is acceptable since the schema carries the burden. Baseline 3 is appropriate.

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 first sentence states a specific verb and resource: 'Create a time block (experimental) and get its id back.' It distinguishes this creation tool from its sibling get_today_time_blocks by making the outcome (returning the id) explicit, and frames how the id feeds into create_task/update_task, locating it in the tool family without ambiguity.

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 clear workflow context: the returned time_block_id can be used directly as time_block_section in create_task/update_task, avoiding an extra get_today_time_blocks call. It also warns that the endpoint is experimental and that the agent should verify the block in the app. It stops short of explicitly naming alternatives or stating when not to use it, so it misses the top score.

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