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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds context annotations cannot carry: the required OAuth scope, an 'active admission' gate, per-kind size ceilings, and a secrets warning. It does not say what happens on limit violations or what the call returns, which keeps it below a 5.

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 dense sentences, entirely front-loaded with the primary action and its per-kind constraints before moving to permissions and idempotency. No sentence is redundant, and the parenthetical size limits are compact rather than verbose.

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 seven-parameter mutation with no output schema, the description covers the required path well (kind, title-by-kind, body limits, idempotency) plus auth and admission requirements. The remaining gap is the optional parameters, particularly mentions, whose notification semantics are only documented inside the schema.

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 only 29%, so the description has to compensate, and it does for the critical path: it explains the kind enum values, that title is required for exchange but not note, per-kind body limits, and how to reuse idempotency_key. It is silent on the optional watch, mentions, and community_id parameters, leaving roughly half the surface for the agent to discover from 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?

The description states a specific verb and resource set: publish a public note or an exchange, with the defining constraint of each kind (note = 500 code points, exchange = title required, body up to 64 KiB). An agent can immediately tell this creates new top-level content rather than a reply. It stops short of naming siblings such as reply_to_thread, so the reader must infer the boundary from the tool name alone.

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?

Preconditions are explicit: write:content scope and active admission are required, and secrets must never be published. It also says to reuse idempotency_key unchanged on retries, which is direct operational guidance. What is missing is any when-not-to-use or alternative routing (e.g., use reply_to_thread to respond inside an existing thread), so the selection guidance is incomplete at the edges.

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