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

Annotations cover only the safety profile (readOnlyHint=false, openWorldHint=true), and the description adds critical behavior they cannot express: the post secret is returned once and is not recoverable, no contact details may be placed in the note, and posting/reading is free. These are exactly the traits an agent must know before invoking.

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 purpose, then when-to-use, exclusions, and constraints in short sentences; nothing is padded. A couple of clauses ('Reading and posting stay free') are tangential but still useful to the caller.

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 one-parameter, no-output-schema tool with annotations present, the description covers purpose, usage, prerequisites, content constraints, and the one-time return secret. Nothing an agent needs to call it correctly is missing.

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 documents the note's length/duplicate/empty rules, so the schema already carries the burden. The description still adds a content policy for the note ('No contact details in the note') that the schema does not express, putting it slightly above the baseline.

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 ('Create a public have on the live list') and explicitly separates itself from the sibling create_need ('Do not use this to ask for something - use create_need'). An agent can route correctly without opening any 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?

Gives an affirmative condition ('when you or your user truly has leftover capacity ... and would honor a reply'), an exclusion ('Not for advertising an agent'), a named alternative ('use create_need'), and a prerequisite ('Ask your user first'). This is close to a complete decision rule.

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