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

The description adds behavioral context beyond annotations: it discloses that the tool returns presigned PUT URLs, requires direct HTTP upload, and that files go live immediately on PUT completion with no separate publish call. The annotations (readOnlyHint=false, destructiveHint=true) are consistent with the mutation described. No contradictions.

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 is compact—four sentences that cover purpose, workflow, return value, and timing. It front-loads the core action and uses a concrete curl example, making it efficient and informative.

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, the description appropriately explains the return value (presigned URLs per file) and the delivery mechanism. It also provides critical timing information ('go live immediately') and the intended post-regeneration context. Minor gaps like error handling or what happens on partial failure are not covered, but for a tool with moderate complexity this is sufficient.

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?

The description calls out tenantId and manifest with path/size/contentType, which mirrors the schema, but does not explain sessionToken or expiresSeconds beyond their schema descriptions. Since schema coverage is 75%, the description adds modest clarity on the manifest structure but relies on schema for the rest. Overall it doesn't significantly exceed the schema's parameter documentation.

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 uses a specific verb phrase 'Add or replace files on an EXISTING roost' and distinguishes from sibling tools by noting Hatch does not schedule regenerations and this is for after local regeneration. This clearly identifies the tool's function and separates it from deploy/hatch.

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 states an explicit use case: 'Use after regenerating a dashboard locally; Hatch does not schedule regenerations.' This tells the agent when to invoke this tool. It also implies not for creating new sites by emphasizing 'EXISTING.' It doesn't explicitly name alternative tools, but gives clear contextual guidance.

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