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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds a behavioral trait: the list changes rarely and should not be re-read. This goes beyond the annotation by warning about staleness and unnecessary repeated calls, which is valuable operational context.

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, compact sentence in Russian conveys the resource, the return fields, the use case, and a caching guideline. Every clause earns its place; no filler or repetition.

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 zero-parameter read-only list tool with an output schema present, the description is sufficient on its own. It states what is returned, when to invoke it, and notes the infrequent change rate. Nothing an agent needs to call this correctly is missing.

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 are zero parameters, so the schema requires no further explanation; the context signal confirms 100% schema coverage. The description's note that the output provides project_id is helpful for downstream usage, though it does not describe input parameters (there are none).

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 names the resource ('Проекты пользователя' – user projects) and the returned fields (id, name, last activity, open tasks). It stops short of an explicit verb like 'list' or 'get', but the tool name and content make the purpose clear. It differentiates from sibling tools like list_files and list_tasks by focusing exclusively on projects.

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 phrase 'Нужен project_id — сюда' gives an explicit trigger for when to use this tool: when a project_id is needed. It also advises 'список меняется редко, не перечитывай', indicating when not to re-fetch. It does not name alternative tools for the same task, but the usage context is clear.

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