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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description usefully discloses that the response is decomposed into parts rather than a flat record. It says nothing about failure behavior when a template has no default nine-slice, which is the main open behavioral question for a 'default' lookup.

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 sentences, no filler, with the primary operation stated first and the follow-up workflow hint second. Every clause carries information an agent can act on.

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 partially compensates by noting the result includes parts, and combined with the read-only annotations and a single scalar parameter, an agent has enough to call this correctly. The absence of an error-mode note is minor for a simple read.

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 0% for the single required parameter templateId, and the description only echoes 'for a template' without clarifying what a template is here, whether the id must reference an existing template, or how the default is selected. Meaning beyond the schema is essentially nil.

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 ('Get the default nine-slice for a template') and adds scope that separates it from the id-based sibling get_nineslice: this returns the template's default plus its parts. It stops short of naming that sibling outright, so differentiation is implied rather than explicit.

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 second sentence gives actionable context — use the returned parts as the seed when creating a new nine-slice, which routes the agent toward create_nineslice. It does not state when NOT to use this (e.g., fetching an existing nine-slice by id via get_nineslice), so exclusions are missing.

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