List this key's fmrl.site pages

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

Annotations already declare readOnly, idempotent, non-destructive, openWorld, so the description's value is in the extras it supplies: the 50-item ceiling, newest-first ordering, and the non-obvious behavior that private pages return their title and a link carrying the key after '#p=' only when this machine holds the key ring. It does not discuss what happens when the key ring is absent beyond implying degradation, which keeps it just short of a 5.

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 verb, resource, ordering and cap in the first clause, then usage, then the private-page caveat, then exclusions. Four dense sentences with little waste, though the private-page sentence is long enough that it could be split for scanning.

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 zero-parameter, read-only list tool with an output schema and full annotations, the description covers everything an agent needs: scope, ordering, ceiling, returned fields, visibility caveat, and routing to siblings. Return-value details beyond that are already carried by the output schema.

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?

The tool takes zero parameters, so there is no parameter meaning for the description to add; baseline is 4. The schema is empty and fully described, and nothing in the description misleads about inputs.

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 ('List the pages') plus scope ('this key owns'), ordering ('newest first'), cap ('50 at most'), and the fields returned (link, status, expiry). It also distinguishes itself from fmrl_get and fmrl_inbox by naming what it does NOT return.

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 an explicit trigger ('when the person asks for a page they shared earlier') and an explicit exclusion with named alternatives: pages others shared with you are not listed here, use fmrl_get to open them and fmrl_inbox for revisions. This is a full when/when-not/alternative mapping.

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