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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so the bar is lower, and the description adds genuinely new behavioral facts: the minimum content requirement, that share_with_team targets the API key's team workspace and the key must belong to one, and that the operation is free. It does not note that repeated calls (idempotentHint=false) create distinct templates, which is the one remaining behavioral 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?

Three sentences, front-loaded with what the tool does and what it produces, followed by prerequisites and the sharing/cost notes. No filler and no repetition of schema-declared field meanings.

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 10 parameters, no output schema and annotations already covering the safety profile, the description supplies the pieces an agent actually needs: the minimum content requirement, the sharing constraint, and cost. It omits any indication of what is returned (e.g. a template id) and duplicate-creation behavior, but neither is critical for correct invocation.

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%, so the baseline is 3, but the description goes beyond the schema by adding the cross-field validation rule (at least one of topic / key_points / extra_direction) and the constraint that team sharing only works if the key belongs to a workspace. That is meaningful semantics the schema fields alone don't express.

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 gives a specific verb+resource ('Save a brief as a named template') and clarifies what a template is by pointing at the app's Brief panel, which separates it from siblings like generate_content and create_outline. It stops short of explicitly naming the adjacent list_brief_templates / delete_brief_template siblings, so it's clear rather than fully differentiated.

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 states a real prerequisite ('needs at least a topic, key points or extra direction') which helps an agent decide whether the call will succeed. However, it gives no when-to-use-vs-alternative guidance — nothing about when to template versus generating directly, or how this relates to the other brief-template tools.

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