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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), the description discloses the auth scope required ('projects:write'), the downstream effect (project chats can consume the note), and the failure mode for duplicates. That is genuine context the annotations do not carry; only the return shape is left unspecified.

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?

Four short sentences, front-loaded with the action, then effect, then failure rule, then auth. Nothing is padded, though the phrasing 'the knowledge of one of your Besidka projects' is slightly indirect where a plainer construction would read faster.

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 four-parameter write with full schema coverage and no output schema, the description covers purpose, effect, auth, and the duplicate edge case. What is missing is minor: whether the created note is returned or how it identifies itself for later update via update_project_knowledge_item.

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% and every parameter — including the optional 'description' — is documented inline with types and lengths. The description adds no additional meaning about parameter usage or constraints, so the baseline of 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?

States a specific verb and resource ('Add a note to the knowledge of one of your Besidka projects') and scopes it to the project-knowledge store, which distinguishes it from add_memory and add_project_text. It stops short of naming those siblings explicitly, so an agent must still infer the boundary from context.

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?

'Chats in the project can then use it' implies the reason to use this rather than a free-form chat message, and the duplicate-refusal rule implies a when-not condition. However, no alternative tool is named and there is no explicit statement about when to prefer add_project_text or update_project_knowledge_item instead.

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