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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false. The description adds useful context beyond annotations: it warns about public accessibility in a public Space, mentions authorization, and implies existing content is overwritten. It doesn't cover response format or error behavior, but with rich annotations this is a solid addition.

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?

Two tightly written sentences with zero waste. The primary action and its risk profile are front-loaded, and the read-first advice follows logically.

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?

Given the destructive nature, rich annotations, and fully described input schema with no output schema, the description is complete enough for an agent to call it correctly. It covers purpose, behavioral risk, and a key precaution without needing to explain return values.

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 all six parameters are documented in the schema. The description mentions 'markdown content/title' but adds no syntax, format, or interaction details beyond what the schema already provides, making 3 the appropriate baseline.

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 states a specific verb ('replace or update') and resource ('markdown content/title of an existing Space document'), and explicitly limits to existing documents, distinguishing it from create-space-document. An agent can tell what it does without opening the 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?

It gives a clear usage context ('when the user wants to replace or update...') and adds a precaution ('Read the document first when preserving existing content matters'). However, it does not name alternative tools or explicitly state when not to use this tool, so it falls short of the full 5-level explicitness.

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