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

Annotations already mark this as non-read-only, idempotent, and non-destructive. The description adds useful behavioral detail beyond that: only the path company's grant is touched, other member grants are unchanged, and NONE is rejected as an access_level. This is valuable context even though it does not discuss auth, rate limits, or response content.

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 leads with the core action, then uses three tight bullets for scope, access_level, and eligibility, plus the endpoint. Every sentence carries information an agent needs, with no filler or redundant restatement of the tool name or schema.

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 4-parameter write operation with no output schema, the description plus the schema fully covers what the tool does, which parameters are needed, and the rules for eligible members and access levels. An agent has enough to select and invoke it correctly without consulting additional documentation.

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 description coverage is 75%, so the parameter descriptions in the schema already do useful work. The tool description supplements them by explaining the access_level enum values, explicitly rejecting NONE, and clarifying that the company is not repeated in the body because it is in the path.

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 ('Grants') and a specific resource: a MEMBER's grant for one company, with the option to change the access_level. The scope line 'Only the company in the path is touched' and the endpoint make the purpose unambiguous and distinguish it from broader member or managed-access operations.

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?

Explicitly says this tool is for granting or updating MEMBER grants and gives a clear exclusion: OWNER and ADMIN 'cannot receive grants.' It also points to the alternative removal path by stating that NONE is not accepted and access should be removed by deleting the grant, which orients the agent toward the sibling deletion tool.

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