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

Annotations already mark this read-only, and the description adds useful boundaries: it returns only card-level metadata, not paid body content, and only for live guides. This goes beyond the structured annotations without contradicting them.

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 description is a single front-loaded sentence with no filler, and the payload restriction appears early. The truncated slug list is a minor inefficiency but still serves a purpose.

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 simple one-parameter read-only getter with an output schema, the description is nearly complete. It covers the resource scope, content boundary, and known slugs; only explicit not-found/error behavior is absent, but that is largely inferable from 'one live guide'.

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 coverage for the single slug parameter is 100%, so the schema already documents the parameter. The description adds a partial list of known slugs, which is helpful but not a complete enumeration, so it improves but does not substantially elevate meaning beyond schema.

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 states a specific verb ('Returns'), a precise resource ('one live guide's metadata'), and enumerates the exact fields returned, which clearly distinguishes get_guide from its siblings get_library_work, get_magazine_piece, and search_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?

The intended use is clear: pass a known guide slug to retrieve card-level metadata. It does not explicitly mention when not to use it or name alternatives, but the 'known slugs' and 'never the paid body/depth content' wording gives sufficient context for an agent to select it over search or content-access tools.

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