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

Annotations already mark destructiveHint=true; the description adds important behavior beyond that: existing sections are replaced, missing sections are appended, the approval flow is disclosed (write-tier, manager approval, from-now-on vs just-once), and the result contains an open link to the updated file. No contradiction with annotations.

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?

The description front-loads the core action and behavior, then groups use cases, routing, and approval into compact blocks with no filler. Each sentence adds operational value.

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 no output schema, it correctly discloses that the result includes the /knowledge?slug= link, and it covers prerequisites and approval behavior. It doesn't cover error cases (e.g., missing file) or the full response shape, but it is complete enough for safe 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% with well-described parameters, so the baseline is 3. The description reinforces the section_header semantics (replace vs append) and new_content behavior, but adds little unique parameter explanation beyond what the schema already provides.

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 opens with a precise verb and resource: 'Update a specific section of a knowledge file by its ## header.' It further clarifies exact behavior (replace if exists, append if not), which sharply distinguishes this surgical tool from full-file knowledge tools like save_knowledge or delete_knowledge.

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 gives explicit when-to-use scenarios ('append a sitting debrief... without rewriting the entire file', 'surgical edits to guidelines or strategies') and a routing prerequisite: 'Call read_knowledge first to see the file's available ## section headers.' This is clear guidance on when and how to use the tool.

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