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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine context by naming the payload contents (schema, size, indices, projections) and the backing Atlas endpoint, but says nothing about auth requirements, failure behavior for unknown ids, or rate limits.

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?

Two compact sentences: the payload summary is front-loaded and the API mapping trails as a secondary detail. Every clause carries information with no filler.

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 what comes back (schema, size, indices, projections), which is the main gap a caller would otherwise face. It is complete enough for a single-parameter read, losing only edge-case behavior for invalid ids.

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 dataset_id (a UUID) is already fully documented in the schema. The description adds nothing about the id's format or source beyond what the schema states; baseline 3 applies when the schema does the heavy lifting.

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 ('Fetch a dataset... by id') plus a useful terminology bridge ('Atlas calls it a project') that maps the user-facing concept to the underlying API noun. The 'by id' qualifier implicitly separates it from nomic_get_dataset_by_slug, though it never names that sibling, so it falls short of a 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?

Usage is only implied: an agent can infer 'use this when you have a dataset id'. There is no explicit when-to-use statement and no routing to the obvious alternative, nomic_get_dataset_by_slug, even though that sibling exists and is the natural wrong choice.

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