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

The annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds a useful behavioral hint that the public list is long and should be filtered or paged, but says nothing about auth requirements, rate limits, or what the paging cursor looks like. Given the annotated baseline, adding one relevant trait merits a 3.

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 compact sentences with the resource and returned fields front-loaded, followed by the paging advice and the HTTP endpoint. Every sentence carries information, though the trailing 'GET /template' is marginal for an agent that already has structured parameters.

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 usefully enumerates the returned fields, and the filter/paging guidance covers the main operational concern for a 5-param list call. Zone defaulting, limit bounds, and visibility semantics are left to the schema, which is acceptable since coverage there is complete. Nothing critical is missing for correct 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 description coverage is 100%, so all five parameters are already documented, including zone default, limit range/meaning, offset next_offset hint, family example, and visibility enum. The description only reiterates 'filter by family or page with limit/offset' without adding format or edge-case meaning beyond the schema. Baseline 3 is appropriate.

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 ('List the compute templates (OS images) of a zone') and enumerates the fields returned (name, family, version, default user, size, visibility). It effectively distinguishes itself from the singular exoscale_get_template sibling by scoping to zone-level listing. It stops short of explicitly naming that sibling, which keeps it at 4 rather than 5.

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?

Provides a concrete reason to use the filters ('The public list is long: filter by family or page with limit/offset'), which is genuine usage guidance. However, it never states when to prefer this over exoscale_get_template or other list tools, and offers no exclusions. Adequate but leaves alternative-selection to inference.

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