zim_metadata

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

Beyond the readOnlyHint=true annotation, the description discloses the full response shape (metadata dict, namespaces list, archive_identity, index_capabilities), the conditional omission of counter_breakdown, the deliberate exclusion of main_page_path with rationale, and a structured error envelope for invalid input. No contradiction with the read-only / non-open-world annotations.

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 purpose is front-loaded and the body is cleanly sectioned (PARAMETERS, RESPONSE, ERRORS, ALIASES) with bolded callouts for the main_page_path exclusion. The length is justified because the RESPONSE section carries documentation that would otherwise be missing given there is no output schema; every sentence adds value.

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 single-parameter, read-only tool with no output schema, the description is remarkably complete: it documents response fields, conditional fields, exclusions and their rationale, error behavior, aliases, and the legacy tools it replaces. Nothing an agent needs to invoke it correctly appears to be missing.

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%, so the description must compensate; it states the parameter is REQUIRED and identifies 'the archive to inspect', which adds only modest meaning over the self-descriptive name zim_file_path. It doesn't specify the expected form (local path vs identifier) or resolution behavior, though the error note softens this gap.

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 opens with a specific verb-resource pair ('Inspect a ZIM archive's metadata + namespace inventory') and details the exact payload (M-namespace fields plus per-namespace counts). It distinguishes itself from siblings by explicitly excluding main_page_path and routing that need to zim_get, and it lists natural-language aliases to aid intent matching.

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?

Provides explicit routing guidance: the ALIASES section tells callers to 'Route through THIS tool' for phrases like 'what's in this zim', and the main_page_path note gives a concrete when-not with an alternative (zim_get(main_page=True)). It also documents that it replaces the legacy get_zim_metadata + list_namespaces pair.

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