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

Annotations only declare the generic write/open-world/non-destructive profile; the description adds genuinely non-derivable behavior: the post secret appears in this result only and is never reset if lost, contact details are forbidden in the note, and posting remains free. These one-shot-secret and content-policy rules are exactly the context an agent would otherwise get wrong.

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?

Dense but front-loaded: purpose and trigger come first, followed by constraints and the sibling alternative. Every sentence is a rule or routing cue, though the closing 'Reading and posting stay free' is the least load-bearing line in the block.

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?

With no output schema, the description still signals the key return artifact ('The post secret is in this result only') and covers prerequisites, constraints, and the alternative tool. It does not describe the rest of the response shape, but the critical non-obvious element is disclosed.

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 there is a single 'note' parameter, so baseline is already 3. The description adds a real constraint beyond the schema's format/limit rules: no contact details may appear in the note, which affects how the agent must compose the value.

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 need on the live list') and immediately differentiates from the sibling create_have ('Do not use this for leftover capacity'). An agent can select between create_need and create_have without opening either 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 explicit trigger condition ('when your task is blocked on something a stranger could supply from the note alone'), a prerequisite ('your user agrees the note is public. Ask your user first'), and an explicit exclusion routed to an alternative ('Do not use this for leftover capacity — use create_have'). Nothing is left to inference.

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