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

The annotations already declare this as a read-only, non-destructive operation. The description adds useful behavioral detail by enumerating what the fetch returns: title, full text representation, source url, and structured metadata. This is valuable because there is no output schema to convey that information.

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 sentences with no filler. The first sentence states exactly when to use the tool, and the second gives the required input and expected output. It is front-loaded and every clause earns its place.

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 tool with one required parameter, read-only annotations, and no output schema, this description is complete. It tells the agent the source of the id, the id format, and the fields that will be returned, covering everything needed to call it correctly.

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 the schema already describes the `id` parameter with its pattern and an example. The description reinforces that the id comes from `search` but does not add significant new meaning beyond what the input schema already states, so baseline 3 is appropriate.

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 clearly states the tool's function: retrieve the full content of a search result using a prefixed id. It also distinguishes this from the sibling `search` tool, which presumably returns lighter results, making the purpose unambiguous.

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 description explicitly tells the agent when to use this tool ('when you need the full content of a search result') and explains that the id must come from `search`. It doesn't explicitly name alternatives it should not be used for, but the context is clear and sufficient.

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