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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so safety is covered; the description earns credit by disclosing what is actually returned and how it is framed — shelf-marked results ('each marked against the shelf', 'issue read and when'), reading-order sequencing with 'what is next', and that this_week puts the pull list first. It doesn't mention rate limits, external-service failure modes, or how large result sets are paged beyond the 'next page' param.

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 core framing before the per-action breakdown, and every clause carries information; there is no filler. The dense semicolon-and-quote style makes it slower to parse than a bulleted action list would be, which keeps it from a 5.

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 seven-parameter, seven-action, read-only tool with no output schema, the description covers what each action yields and where the data comes from, which is what an agent needs to pick an action and fill params. Gaps are modest: paging semantics beyond the 'page' param and behavior when a name lookup is ambiguous or missing are not addressed.

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 100% and each property already names the actions it applies to, so the description's per-action phrasing largely restates that mapping. It adds minor meaning — 'issue number as printed' style usage, date as 'any day of the week', and id 'from an earlier answer' — but nothing substantial beyond the schema, so the baseline 3 applies.

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+resource ('Explore comics beyond their shelf, from Metron') and then enumerates every action with what each returns, so an agent can tell 'issue' apart from 'creator'/'arc'/'this_week'/'reading_orders' without opening the schema. It also names the data source and ties it to the sibling family (set_progress, add_item).

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 routing: logging reading goes to set_progress with media_type 'comic', and missing series come with metron ids 'for add_item'. What's missing is a statement of when to use this over adjacent discovery siblings like search_library, get_details, or lookup_item, so the alternatives guidance is partial rather than complete.

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