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

Annotations already cover the safety profile (non-read-only, non-destructive, non-idempotent), and the description adds real context: the handoff is a durable board note intended for a future session, and `summary` must be an authored recap rather than a transcript. It stops short of saying what object is created or whether repeated calls create duplicate handoffs, which matters given idempotentHint=false.

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?

Front-loaded with the definition and the timing instruction, then trigger phrases, then the summary constraint. Every sentence has a job, though the `summary` warning partially duplicates the schema text and could be trimmed.

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 3-parameter mutation tool with no output schema, the description covers purpose, timing, trigger phrases, and content expectations well. It leaves the return value (e.g., a handoff ID) and duplicate-call behavior unstated, minor gaps but real ones for a save operation.

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 coverage is 100% and the schema descriptions already define `summary` as an authored done/next/blocked recap that is not a transcript, plus `links` examples and limits. The description largely restates the `summary` constraint with added emphasis ('YOUR OWN', 'list of raw messages') rather than adding new parameter semantics, so 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 (save a session handoff) and defines the artifact concretely: a durable note capturing done / next / blocked / key links. It is clearly distinct from every sibling, which are task/board/comment CRUD operations, and even defines the required content of the record.

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?

Explicitly says when to call it ('at the END of a working session so the next session can pick up') and supplies concrete trigger phrases the user might say. No sibling tool offers an alternative for this need, so the absence of a 'use X instead' line is not a gap.

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