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

Annotations already declare readOnly/openWorld/idempotent/non-destructive behavior. The description adds meaningful context beyond that by specifying the scope ('every long-form essay'), the source domain, and the types of metadata returned. It does not contradict the annotations but also does not detail potential edge cases such as pagination or ordering, though the output schema likely covers much of that.

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: one sentence states what the tool returns and its scope, and a second sentence gives routing guidance. Every sentence adds value, and the core action is front-loaded.

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?

For a simple list tool with one optional parameter, full schema coverage, a rich output schema, and safety annotations, the description covers the essentials: scope, returned fields, and when to choose the sibling tool. Nothing critical is missing for an agent to call it correctly.

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% for the single optional locale parameter, with a clear description of enum values and the omit behavior. The tool description itself does not mention the parameter, but the schema already fully explains it, so the baseline of 3 applies.

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 clearly states the verb ('List'), the resource ('every long-form essay published on articles.santismm.com'), and the returned attributes (language, dates, topics, canonical URLs). It also distinguishes itself from search_articles by mentioning the slug/topic distinction, so an agent can confidently tell this tool apart from siblings.

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 explicitly says when to use this tool ('Use this to browse the essay catalogue') and when to use the alternative ('use search_articles when you have a topic rather than a slug'). This direct routing removes ambiguity and makes the choice between sibling tools straightforward.

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