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

With no annotations, the description carries the full burden and does well: it discloses the required permission (crm:read) and the 404 behavior for foreign or missing IDs. This is meaningful behavioral context beyond the raw schema, though it does not describe response shape or pagination.

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, front-loaded with the primary purpose, followed by permission and error behavior. Every sentence earns its place and there is 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?

For a simple two-parameter get operation, the description covers purpose, scope, required permission, and a key error case. It does not explicitly describe the return value, but no output schema is provided and 'Reads one activity' reasonably implies the activity object is returned.

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 100%, so the baseline is 3 even though the schema's parameter descriptions are only the parameter names. The description adds context by tying the tool to the organization and tenant CRM, but it does not clarify formats, constraints, or how the IDs relate beyond what the schema already names.

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 uses a specific verb ('Reads'), a clear resource ('one activity'), and a scope ('from the tenant CRM'), which distinguishes it from list/create/update/delete siblings. The singular 'one activity' makes the tool's role unambiguous even without opening the schema.

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 clearly implies this is the tool for retrieving a single activity by ID, and the sibling names for listing/creating/updating/deleting provide natural contrast. It also states the required crm:read permission, but it does not explicitly say 'use list for multiple activities' or name an alternative.

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