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

With readOnlyHint=true already covering the safety profile, the description still adds real substance: it discloses that Library API keys are redacted (preventing an agent from expecting secrets) and names the exact upstream endpoint GET /videolibrary. It does not discuss pagination behavior or rate limits, which keeps it below 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?

One front-loaded sentence enumerating the returned fields, followed by a short redaction note and the endpoint identifier. No filler, and the most decision-relevant information comes first.

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?

With no output schema, the description usefully previews the returned shape (counts, usage, zones, settings) and the redaction caveat. Pagination and filtering behavior are covered by the parameter schema, so the only minor gap is a lack of guidance on result volume or ordering.

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%, with page, per_page, and search each documented, including defaults and ranges. The description adds no additional parameter meaning, so the baseline of 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 (List) and resource (Stream video libraries) and enumerates the returned data: video count, storage/traffic usage, linked zones, player/encoding settings. This distinguishes it from the singular sibling bunny_get_video_library, which clearly fetches one library.

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?

Usage is implied by 'List the Stream video libraries' — an agent can infer this is the enumeration path versus bunny_get_video_library for a single library — but no explicit when-to-use or when-not guidance is provided, and no exclusions are stated.

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