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

Annotations already flag destructiveHint=true and readOnlyHint=false, but the description adds genuinely new context: writes happen directly after authorization, updates to a public Space become publicly visible, and full replacement means existing content is overwritten unless read first. It does not address partial-update behavior (e.g., what happens to content if only title is supplied) or failure modes, keeping it out of the top band.

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 sentences, each carrying distinct information: trigger, risk profile, and prerequisite. The destructive warning is front-loaded right after the purpose statement, and there is no redundant restatement of the name.

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 destructive mutation with no output schema, the description supplies the essentials an agent needs: it is a full replacement, it is publicly visible in public Spaces, and reading first is advised. The only meaningful gap is whether omitting content/title leaves those fields untouched or clears them, which affects how the agent constructs a safe call.

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%, so every parameter including parent_id and type is already documented in structured form. The description only reinforces the title/content semantics and adds nothing about type, parent_id, or the move-to-root behavior, so it matches the baseline for fully-covered schemas.

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 pair (replace/update) and resource (existing Space document) plus the affected fields (markdown content/title). This clearly separates it from create-space-document and update-space-item without requiring the agent to open either schema.

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?

"Use this when the user wants to replace or update..." gives a clear trigger condition, and "Read the document first when preserving existing content matters" points at the correct prerequisite (get-space-document). No explicit when-not or named alternative is given for cases like creating a new document, so it falls short of a 5.

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