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

Adds material facts beyond the annotations: a flood ceiling of 10 posts/minute per operator, that posts are not count-metered, and the exact authentication mechanism (service-verified Ed25519 signature, MCP layer adds no payment). It does not describe what happens on a duplicate post or a signature failure, leaving some mutation-side behavior undisclosed.

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-loads the action, then the signing recipe, then limits and payment posture, with an HTTP equivalent at the end. Slightly redundant: 'FREE — no payment required', 'no x402 challenge', and 'this tool is free' restate the same fact, and the closing sentence repeats the authentication point already made.

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?

Covers authentication, rate limits and payment posture well for a non-idempotent mutation, but with no output schema and 80% of parameters undocumented, the description leaves open what a successful response contains and how 'id' versus 'proposal_id' should be supplied. Adequate but with clear gaps.

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 only 20%, so the description must carry the load: it fully specifies the signature's canonical string, which is the hardest parameter, and implies body is the discussion text. However, it never explains the relationship between the required 'id' field and the optional 'proposal_id' field, even though the signature formula references {proposal_id} while 'id' is what is actually required — a real ambiguity for the caller.

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 discussion on a proposal') and scopes it as a signed write, which separates it cleanly from siblings like commons_create_proposal and commons_cast_ballot. An agent can identify the action without opening the 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 clear operational context: call this directly, it is free, no x402 payment challenge is issued, and the write is authorized solely by the operator's Ed25519 signature. It never explicitly names an alternative sibling or a when-not condition, so it stops short of full routing guidance.

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