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

Annotations already declare the write/safe/non-idempotent profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds genuine behavioral context beyond that: where the entry surfaces (Activity page, next chat overview), the 800-character cap, and the audience it is written for. It does not clarify dedup/repeat-call behavior.

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?

Three dense sentences, front-loaded with the action and trigger, followed by format/audience constraints and a short prohibition. No filler; every clause carries information.

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 2-param write tool with no output schema and annotations covering safety, the description supplies the content, audience, visibility, and limits an agent needs to call it correctly. Minor gaps remain around return behavior and duplicate handling.

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 50%: "server" is documented in the schema, but "summary" has no schema description. The description compensates well, defining the required content (what you did, what changed, what is left), length, and plain-language register for the undocumented required param.

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 ("Write down finished work") and adds the trigger condition "when a task that changed something is done," so an agent can tell this is a work-progress log distinct from note-keeping siblings like save_note. It does not name a sibling explicitly, so it stops short of a 5.

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 an explicit trigger ("when a task that changed something is done") and a content exclusion ("No passwords or keys"). It never names an alternative tool or a when-not-to-use case, so no explicit routing guidance.

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