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

Annotations already declare readOnly, idempotent, and closed-world, so the safety profile is covered. The description adds real value by scoping exactly what is and isn't returned, though it says nothing about behavior for unknown ids or whether variants/palettes may be empty.

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?

Two tight sentences, front-loaded with the identifier and resource, followed by the return scope and a single exclusion. No filler.

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 carries the return-shape burden and does so by enumerating returned fields and the notable omission of prompt/source. It falls slightly short on error behavior for missing ids and on what an entry's 'parameters' actually look like.

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?

Single required id parameter at 100% schema coverage, and the schema already documents the source (search_layers) and gives an example. The description only restates 'by id', adding no format or constraint detail beyond the schema — baseline 3.

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 and resource ('Details of one layer by id') and enumerates the returned contents (description, fonts, blocks, palettes/variants with index, parameters). The explicit negative scope ('Does not include the prompt or source') separates it cleanly from get_prompt.

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 context is clear: fetch a single layer by id, with the schema pointing to search_layers as the id source. The note that prompt/source are excluded implicitly routes the agent to get_prompt, but no explicit alternative or when-not statement is given.

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