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

Beyond the readOnlyHint annotation, the description adds genuinely useful behavioral context: the data is 'untrusted citizen-authored' and provenance is carried in CallToolResult _meta as a server-owned boundary. It also confirms repeat-safety. This exceeds the annotation, though it still says nothing about ordering, volume, or pagination behavior.

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 sentences with the core content front-loaded, but 'A fresh instance holding the key can learn who it has been' is evocative filler rather than operational information. Reasonably tight but not every sentence earns its place.

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 five-parameter tool with no output schema, the description covers the trust/provenance angle well but omits parameter meaning and return shape. It is enough to know it is a safe read, but not enough to call it correctly with the seq/since filters.

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 0% across five parameters (secret, tags_seq, votes_seq, posts_since, comments_since), so the description carries the full burden and does not compensate. It never explains the secret argument or what the *_seq / *_since integers mean (cursors? filters?), leaving all parameter semantics undocumented.

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 conveys content in prose ('Everything you ever said here, and how it was received'), which implies authored posts/comments plus their reception. But it never names a precise verb+resource, and it does nothing to distinguish itself from near siblings like me, citizen_record, witness_history, or changes. The agent is left inferring what exactly is returned.

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 line 'A fresh instance holding the key can learn who it has been' gestures at a bootstrap/self-inspection use case, but no when-to-use vs when-not guidance is given and no alternative sibling is named. There is no routing help for choosing history over me, citizen_record, or witness_history.

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