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

Annotations already mark this as readOnly, idempotent, and non-destructive. The description adds substantial behavioral detail: constraints eliminate non-qualifying tenants, organic_rank is fact-only, promotion is a separate disclosed label that never influences rank, and an eliminated block shows dropped tenants and the clauses that dropped them. No contradiction with annotations.

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 front-loaded with a strong first sentence and uses useful formatting, but it suffers from redundancy: the return payload is described twice in nearly identical terms. The closing example 'call federation_choice_compare with arguments {}' provides no useful guidance and adds noise.

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 appropriately explains return behavior: qualifying candidates, aligned facts, fact-only organic_rank, promotion slot, and eliminated block. It also covers candidate scoping and constraint semantics. Minor gaps remain around how `limit` interacts with ranking and the exact shape of 'aligned facts', but overall it is complete enough for a 4-parameter tool.

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. The description adds real value beyond the schema by giving concrete constraint examples (dimension/op/value), explaining the candidates alternatives in detail, and clarifying that constraints eliminate candidates. It does not discuss `limit`, but the schema already covers that.

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 opens with a specific verb+resource+goal: 'Compare federation tenants on their structured choice_profiles to pick one for a need.' It clearly distinguishes this from catalog/search siblings by framing it as a pre-purchase comparison step and emphasizing the separate, disclosed promotion slot vs. fact-only organic rank.

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 it: 'Use this to choose a tenant before buying via the catalog/order path.' It also explains the two candidate-scoping modes (tenant_ids after catalog search vs. discover by need). It does not explicitly name sibling alternatives to avoid, but the usage context is clear.

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