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

Annotations already cover the safety profile (readOnly=false, destructive=false, idempotent=false), and the description adds real value beyond them: a plan gate ("Requires the Build plan or higher"), the fallback-to-default behavior of every token field, and the empty-issuerName-to-workspace-name rule. It does not cover failure modes such as duplicate names or whether a repeat call creates a second template, which keeps it short of a 5.

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?

Information is front-loaded: creation, then defaults, then the logoUrl constraint, then composition semantics, then the plan gate. Dense but every sentence carries a distinct rule; the composition clause is slightly packed, costing a point.

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 an output schema present, return values need no explanation, and the description covers the non-obvious creation-time constraints (plan requirement, defaults, image formats, coordinate system) for a 2-parameter tool with a very deep nested tokens object. What is missing, error and duplicate-name behavior, is minor.

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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning the schema cannot: positions coordinates are page fractions inside the margin, x is the element centre, y its top, w its width, and freeform:true switches from layout to positions. It also documents the PNG/JPEG-only logoUrl constraint that the schema only expresses as a generic uri format.

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 ("Creates a certificate template") that cleanly separates it from update_certificate, get_certificate and delete_certificate in the sibling list. An agent can identify the operation 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?

The description explains defaults, format constraints and the plan prerequisite, so an agent knows the preconditions for calling it, but it never says when to choose create_certificate over update_certificate or how to handle an existing template. Usage is implied by the verb rather than spelled out.

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