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

Annotations already declare readOnlyHint and destructiveHint=false, and the description reinforces this with 'opens nothing by itself', which is the key behavioral fact an agent needs. It also discloses that no self-serve API key or onboarding guide exists, pre-empting a wrong turn toward an API integration. It does not describe the shape or length of the returned instructions, leaving that partly to inference.

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 sentences, front-loaded with the purpose and immediately qualified by what the tool actually does. Every sentence carries information: the step-by-step return, the no-side-effect guarantee, the follow-on browser tools, and the API caveat. Nothing is repeated from the annotations.

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 zero-argument, read-only guidance tool with no output schema, the description covers everything an agent needs: what it returns, that it changes nothing, and what to invoke next to complete the action. The lack of an output schema is acceptable because the return format is described qualitatively as screens, buttons, and fields.

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?

The tool takes zero parameters, so there is no parameter semantics to explain and the baseline of 4 applies. The description correctly implies no inputs are needed, even though target client or note text must be supplied elsewhere in the conversation.

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 title phrase 'Add client note' is immediately redefined: the tool 'Returns how to do it in Paired Plus step by step (screens, buttons, fields) and opens nothing by itself.' That correction is specific and actionable, so an agent understands this produces guidance, not a mutation. It stops short of contrasting itself with the many other paired_plus_* guidance tools, so the reader must infer the difference from the note-only wording.

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 names the follow-on path explicitly ('then do it with the cotlet_browser_* tools in the user's Paired Plus Cloud Browser'), which is genuine routing guidance. It never states when to prefer this over a sibling or when it is unnecessary, and the closing line about the official API is context rather than a use condition. Guidance is implied by the workflow, not spelled out.

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