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

Beyond the annotations (readOnly=false, destructive=false, idempotent=false), the description discloses a 280-character cap, a 20-note retention limit, newest-first ordering, visibility on the goal page while active or complete, no cost on any plan, and that nobody is notified. That is substantive behavioral context an agent cannot get from the structured fields.

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 short sentences, zero redundancy, with the core action and size constraint front-loaded before the retention and visibility details. Every sentence adds distinct 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?

An output schema exists, so return values need not be explained, and the annotations cover the safety profile. The description covers limits, retention, and visibility well, though it never clarifies what goalId refers to or whether the target goal must be active — the one remaining gap for a two-parameter mutation.

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% — 'body' is documented in the schema and the description's 280-character statement only echoes its maxLength. The 'goalId' parameter is undocumented in both places, so the description does not compensate for the coverage gap. 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 ('Add a short note') on a specific resource (a goal's progress note) and clarifies what the note contains ('saying what the money did'). An agent can distinguish this from update_goal or delete_goal_update without opening the schema.

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 implies context (a note about what the money did, shown on the goal's page) but never states when to post an update versus updating the goal itself, nor any prerequisite such as the goal needing to exist or be active. Usage is inferable but not spelled out.

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