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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered without the description. The description does add one genuinely useful behavioral fact beyond the annotations: results are sorted by most recent activity. It says nothing about the limit default, truncation, or pagination behavior, which keeps this at a 3.

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?

One sentence, zero waste, with the resource and the sort order front-loaded. Nothing to trim and nothing buried.

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?

This is a simple read-only listing tool with an output schema present, so return-value documentation is unnecessary, and annotations cover safety. The description is complete enough to call correctly; the only minor gap is the absence of any hint about the default page size or what to do when more projects exist than are 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?

There is a single optional 'limit' parameter and schema description coverage is 100%, so the schema already documents it ('How many projects.'). The description adds no meaning about the parameter, such as what happens when the limit is exceeded or how ordering interacts with it. Baseline 3 is appropriate when the schema does the work.

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 ('Lists') and resource ('this workspace's Ad Agent projects'), which clearly separates it from composer_project_get and composer_project_create. It also discloses the ordering ('most recently active first'). It stops short of naming a sibling or restating scope exclusions, so it is clear but not maximally 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?

There is no when-to-use or when-not-to-use guidance. The description never mentions composer_project_get for fetching a single project, nor any condition under which listing is preferred over another tool. Usage is only inferable from the verb.

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