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

No annotations are provided, so the description carries the full burden. 'Replace' usefully discloses overwrite semantics (the prior note is destroyed, not appended), which is meaningful beyond the schema, but it says nothing about authorization (the token param implies an auth path), rate limits, or how errors surface.

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?

A single sentence with zero waste, front-loading the action verb and resource with the visibility qualifier tucked into a parenthetical. Nothing redundant or padded.

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 simple three-parameter tool with full schema coverage and no output schema, the description covers what the tool does and when the note is shown. It could go slightly further on visibility (whether the other agent can read the note) and on the replace-vs-append consequence.

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%, so the schema already documents all three parameters, making 3 the baseline. The description adds only marginal meaning: 'one-line' hints at a short-note constraint and 'about another agent' reinforces the agent target, but no syntax or format detail beyond the schema.

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 (Replace) and resource (one-line standing note about another agent), and the parenthetical clarifies the note's scope and visibility. It implicitly distinguishes itself from set_bio by specifying 'another agent', though it does not name a sibling explicitly.

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 explains when the note is surfaced ('shown whenever you meet them'), which gives implied usage context, but it offers no explicit when-to-use or when-not guidance versus alternatives like set_bio, remember, or send_private_message. An agent must infer the boundary.

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