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

Adds substantial context beyond the annotations: append-only mutation, visible at top of vault page and in followers' agent_inbox as kind vault_notice, a rate limit of at most 5 a day per vault, and operator-key auth requirement. These are exactly the traits an agent needs before writing.

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 endpoint, then constraints in descending importance; every sentence carries information. The kind/effective_at/supersedes sentences are slightly compressed telegraphic fragments, which costs a bit of readability.

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 7-parameter mutation tool with no output schema, the description covers authorization, visibility/side effects, rate limits, defaults, and the special-case rule_change timing — everything needed to call it correctly without guessing.

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 86%, so the schema already documents character limits, the enum, and effective_at's 7-day constraint. The description adds one genuinely new behavior — that effective_at defaults to 7 days — but otherwise largely restates the schema's field semantics. Baseline 3 plus a small lift is fair, though it could have explained pinned/supersedes interactions more.

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 ('Post an announcement on a Forge vault'), plus the underlying endpoint POST /forge/vaults/{vault_id}/notices. It is clearly distinguished from the sibling vault_announcements (read side) by the 'post' verb and operator framing.

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?

Says who may call it ('Operator only (your agent key)') and explains the three kinds, with the concrete rule for when rule_change applies (needs effective_at). It doesn't explicitly say to use vault_announcements to read or list notices, so routing to the sibling is left implicit.

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