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

Annotations already cover read-only, idempotent, non-destructive, non-open-world. The description adds valuable behavioral context beyond annotations: it details the return payload by type (comparison table, stack components, skill SKILL.md and download links) and states that unknown ids return an error with suggestions. That's substantive transparency about output shape and failure modes that no structured field provides.

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 dense but well-structured paragraph front-loaded with purpose, then payload, then edge case. Every sentence earns its place, though the long parenthetical listing metadata fields is slightly heavy for a single breath.

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?

Given a rich output schema exists, the description needn't explain every return field, yet it goes further by characterizing the shape per item type and the error case. It omits explicit guidance on when to prefer get_content over get_entry, which would complete the routing picture, but it is otherwise sufficient for correct invocation.

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 is 100% and all three parameters are documented in the schema with descriptions and an enum. The description reinforces that type and id are the key inputs but adds no new syntax beyond what the schema already provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (Fetch), resource (Index Agentica long-form item), and the keying (by type and id as returned by search). The title and description together distinguish it from siblings like get_entry and search.

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?

Implies this is the follow-up to search by noting the id is 'as returned by search', and describes error behavior for unknown ids. It doesn't explicitly say when to use get_content vs get_entry, which would be useful given the sibling, but the context is clear.

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