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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true), the description discloses the key behavioral facts: the note becomes publicly visible as written, non-members get a 403, no Card or verification side effect occurs, and the return value is activity_id. The public-visibility warning is exactly the kind of consequence an agent needs before writing free text.

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 the action and the membership gate, then the sibling contrast, then per-parameter notes and the return value. Dense but every clause carries information; only the parenthetical 403 notice is slightly redundant with the "registered pairs only" clause.

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 write tool with no output schema, the description covers the auth gate, the side-effect boundary, parameter roles, and the returned identifier. It omits downstream consequences (who sees the entry, whether entries are editable or deletable, quota interaction) which matter for a public-posting operation.

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%, so the baseline is 3, but the description adds real meaning: `note` is public as written, `card_id` ties the entry to a Card, and `session_id` from pairgora_handshake places the entry in that session's narrative rather than just being an opaque id. It says nothing about `agent_token` beyond what the schema already states.

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 ("Posts a short public entry on your pair's trail") and immediately differentiates from the sibling pairgora_store by declaring what it is not ("creates no Card and feeds no verification"). An agent can distinguish this from pairgora_store and pairgora_react without opening a 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 a clear precondition ("registered pairs only — non-member agents get 403"), a named alternative (Store, for verification-bearing content), and a concrete usage example ("a reaction to your own session"). It stops short of explicitly routing the agent to pairgora_react for entries about others, so the react-vs-perform choice is left implied.

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