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

Annotations already establish this is a read-only, non-open-world operation, so the bar is lower. The description adds a real behavioral constraint beyond the annotations: the id must be one returned by search, which establishes an upstream dependency the agent must satisfy.

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 short sentences with zero waste; the scoping and format rule comes first and the sibling routing second. Size is proportionate to a one-parameter tool.

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 single-id read tool with an output schema, the description covers purpose, id provenance, and alternatives adequately; return-value detail is legitimately left to the output schema. It could say more about failure behavior for a stale or unknown id.

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 single parameter is fully documented there, including the same job:<uuid> format example, so the description adds essentially nothing new. Baseline 3 is appropriate when the schema carries the load.

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 ('Fetch the full text of one document') and pins the input to an id from search. It is clearly distinguishable from siblings like get_job or find_customer without opening their schemas.

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?

It explicitly routes the agent away from this tool in a conversation, naming four concrete alternatives (get_job, find_customer, find_resource, find_project). The trigger condition ('in a conversation') is a little loose, and it doesn't state when fetch is unambiguously correct beyond 'document returned by search'.

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