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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds value by disclosing the return payload (content schema + writing guide + limits), which matters because there is no output schema. It doesn't note whether the response is large or cacheable, but that's a minor gap.

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?

A single sentence with no filler, front-loaded with the verb and the exact resource, and the destination sibling named at the end where it belongs.

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 does the necessary work of naming the three returned pieces (schema, writing guide, limits), which is enough for an agent to know what it will receive. Slightly short of 5 because 'writing guide and limits' is left unelaborated and the include_settings branch of the output isn't described.

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% with an enum of 20 activity types, so the schema fully documents both parameters. The description adds only the scoping phrase 'for one activity type' and never mentions include_settings or what the settings catalog contains beyond the schema's own wording. Baseline 3 applies.

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?

Specific verb+resource: 'Get the JSON schema of the "content" argument of set_activity_content for one activity type'. It names the exact payload it supplies (schema plus writing guide and limits) and ties itself to the sibling that consumes that payload, which distinguishes it from get_activity, get_activity_content, and list_activity_types.

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 reference to set_activity_content makes the usage context clear: this is the pre-flight lookup for constructing that call's content argument. However, it never states the imperative ('call this before set_activity_content') nor any when-not conditions such as using list_activity_types for enumeration.

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