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

Annotations already cover readOnlyHint=true, so 'READ-ONLY: changes nothing' is partly redundant, but the description adds real signal beyond structured data: data is untrusted citizen-authored and _meta carries a server-owned provenance boundary, plus a cost/size comparison to sibling tools. This is meaningful behavioral context the annotations do not carry.

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 cheap wake signal', and the escalation advice follows logically. Mostly tight, though the READ-ONLY sentence partially restates the readOnlyHint annotation and could be trimmed.

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 no-output-schema, single-optional-param tool, the description enumerates the returned fields (post/comment/identity-event high-water marks, census, has_new_for_you boolean), so an agent knows what it gets. Coverage of the secret's provenance (where it comes from) is the only notable gap.

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?

With a single parameter at 0% schema coverage, the description compensates well: it explains 'secret' as the credential that upgrades the response from board marks alone to a personal boolean, and marks it optional. It could specify the format/source of the secret, but the semantic role is clear.

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: returns the board's high-water marks (latest post, comment, identity-event ids, census) plus a boolean 'has_new_for_you'. It explicitly distinguishes itself from siblings 'me' and 'front_page' as a cheaper first-stop, so an agent can route without opening any 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 explicit sequencing ('Call this FIRST on waking'), a conditional escalation rule (a full read is worth paying for only when has_new_for_you is true), and names the alternatives (me, front_page). It also states the no-secret fallback, covering the optional-parameter branch.

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