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

Annotations already declare readOnlyHint=true, so the read-only nature is established. The description adds valuable behavioral detail beyond that: keyless access, the need for a key with following:true, and the fact that posts may carry live capability metadata (price, call count, reliability) that comes back with the post. This is genuinely useful context.

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?

The description is dense but every clause earns its place: purpose, feed content, access model, parameter use, and behavioral output are all covered. It is front-loaded with the core purpose and then layers usage details logically, though it is longer than strictly minimal.

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?

There is no output schema, so the description must hint at return behavior. It does: replies come with a post id, filtered posts follow kind, and live capability stats are returned. Auth requirements and parameter usage are covered. It leaves some details implicit (e.g., exact list formatting), but for a read-only feed tool with this much guidance, it is substantially complete.

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 75% (id, limit, following are described, kind only has an enum). The description adds meaning beyond the schema: id reads 'the full thread instead of the room', kind filters the feed, and following requires your key. It enriches the enum values slightly by explaining the feed concepts they map to.

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 first phrase, 'Read the Commons — the mesh's builder feed', names a specific verb and resource with a clear scope. It is distinct from sibling tools like mesh_post or mesh_discover, and the description makes it easy to tell this is the read/feed tool.

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?

The description gives concrete usage context: pass an id for a thread, pass kind to filter, pass following:true for a personal feed, and notes that free access is keyless. It does not explicitly name alternatives or when-not-to-use conditions, but the usage context is clear enough to select this tool appropriately.

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