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

Annotations already declare idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful context beyond them: the content-vs-styling partial-update rule and the fact that updated details come back on success. It does not mention permission requirements, whether unspecified fields are preserved or cleared, or the null-removal behavior documented only in the schema.

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 short sentences with the core action front-loaded and the conditional update rule immediately after. No filler, though the final 'returns updated details' sentence is thin given there is no output schema to describe.

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 mutation tool over a large nested object, the definition covers the essential partial-update semantics and the success outcome, and annotations cover safety/idempotency. It leaves gaps around what happens to omitted fields, null-based removal of logo/gradient/background image, and whether the caller needs auth or ownership of the QR code.

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?

Top-level schema description coverage is reported as 0%, but the nested 'input' object documents ~24 properties in detail, so the schema carries most of the load. The description only groups them into 'content' and 'styling' categories without adding format, enum, or default semantics — useful framing, but no new parameter-level information.

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 (update ... an existing QR code) and scopes it to content and/or styling, which is enough to separate it from generate_qr_code and get_qr_code_by_id. It stops short of naming a sibling or an explicit boundary, 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?

The description implies usage via one behavioral condition ('If content fields are not provided, only styling is updated'), which tells the agent a partial update is legal. It offers no when-to-use vs. alternatives guidance, no prerequisites, and no note on when to prefer generate_qr_code or move_qrcode_to_project.

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