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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is fully covered without the description. The description adds that the payload is a catalog of plans, rates, and top-ups, which tells the agent what kind of data comes back. It says nothing about caching, freshness, or size of the catalog, so the added value is modest.

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?

A single short sentence with no filler, and the resource content is front-loaded. It is arguably too terse for a pricing catalog, but every word present earns its place and nothing is redundant.

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?

This is a simple, zero-parameter, read-only tool, so the description does not need much. However, there is no output schema, so nothing tells the agent what the returned plan/rate/top-up structure looks like or how to use it downstream. For a catalog tool whose whole value is its return shape, that is a real gap.

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 tool takes zero parameters, so there is no parameter semantics to explain and the baseline of 4 applies. The description correctly refrains from inventing argument detail for a no-arg tool.

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 gives a specific verb ('Reads') and enumerates the concrete resource contents: plans, per-result rates, and top-up options. That is far more informative than the bare name get_capacity_catalog. It does not, however, distinguish this from near siblings like get_capacity_entitlements, get_capacity_balance, or get_capacity_quote, so an agent must infer the boundary itself.

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?

There is no when-to-use guidance, no exclusions, and no mention of the many capacity-related siblings. The agent is left to guess whether this catalog is a prerequisite for quote_capacity_work or get_capacity_quote. Only the implicit 'read pricing information' context hints at usage.

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