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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral detail: only *published* vendors are returned, implying unpublished slugs fail. It says nothing about what happens on a miss (error vs empty), and no output schema exists to supplement it.

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?

One sentence, no filler, subject and qualifier ('published') front-loaded. Nothing could be removed without losing meaning.

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 is the only place a return shape could be conveyed, and it doesn't say what fields a vendor record contains or confirm not-found behavior. For a simple slug lookup this is a modest but real gap rather than a blocking one.

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% and the single slug parameter carries its own pattern and length constraints. The description's 'by its slug' restates the schema rather than adding format, normalization, or case-sensitivity guidance, so baseline 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?

Specific verb+resource: 'Get one published education vendor by its slug.' The word 'one' and the singular key-based lookup clearly differentiate it from search_listings, though no sibling is named explicitly.

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?

Usage is implied: fetch a single vendor when you already have its slug. The description never states when to prefer this over search_listings (i.e., when you don't have a slug, or when unpublished records should be included), leaving the routing to inference.

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